Electronic structure simulations. Cell optimizations and phonon calculations for all the supercells of NV\(^-\)  defect in diamond and V\(_\mathrm {B}^-\)  defect in h-BN were performed within the framework of periodic density functional theory using CP2K.[1]} All the optimization and phonon calculations were done at \(\Gamma \) -point. A very tight force convergence criteria of 10\(^{-7}\)  a.u. and SCF convergence criteria of 10\(^{-10}\)  a.u. for the energy were employed for the cell optimizations. A plane wave cutoff of 1000 Ry with DZVP-MOLOPT Gaussian basis sets and Goedecker-Tetter Hutter pseudopotentials were used for both systems. The Perdew-Burke-Ernzerhof (PBE) functional and DFT-D3 methods for dispersion corrections had been used.[2]}, [3]}
